On Mon, 19 Apr 2004, Oliver Neukum wrote: > This somehow doesn't add up. The data structure bound to is the interface > and the real addressing is done to a device/endpoint pair. In fact, why do > we have a pipe member anyway?
The HCDs use it to determine the endpoint number, transfer direction, and transfer type (ctrl, bulk, int, or iso). > Yes, but we must not refcount interfaces. We cannot refcount _any_ data > structure being an internal representation of a physical USB device. > Probe() and disconnect() are entirely software events. I don't see why not. So long as the data structure is marked defunct so that it can't be used for communication with the device after a configuration change (for example), there's nothing wrong with leaving it in memory until its refcount goes to 0. > The most elegant solution would seem to be refcounting URBs. We do that, > but an URB doesn't have an undead state. That would require us to add > an interface argument to usb_alloc_urb(). Then we could zombify URBs and > submissions to ep0 for no driver could be done by allocating URBs with > NULL as an interface parameter. Right now URBs aren't bound to anything when they are created. I've seen proposals that they be bound to endpoints, interfaces, and devices. Are there any possibilities left? Binding URBs to _something_ at or below the HCD level makes sense. Allocation could be handled by the HCD itself, with the necessary hc-private data added automatically (but what about interference with the variable-length iso packet descriptors at the end?). However elegant it may be, though, I don't see any need for _inactive_ URBs to be identified with particular endpoints or interfaces. Alan Stern ------------------------------------------------------- This SF.Net email is sponsored by: IBM Linux Tutorials Free Linux tutorial presented by Daniel Robbins, President and CEO of GenToo technologies. Learn everything from fundamentals to system administration.http://ads.osdn.com/?ad_id=1470&alloc_id=3638&op=click _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
